The young mathematical disciple '' might be of some help in making psychology a real science. - Kurt Zadek Lewin

Even if all the laws of psychology were known, one could make a prediction about the behavior of a man only if in addition to the laws, the special nature of the particular situation were known.

A successful individual typically sets his next goal somewhat but not too much above his last achievement. In this way he steadily raises his level of aspiration... The unsuccessful individual on the other hand, tends to show one of two reactions: he sets his goal very low, frequently below his past achievement... or he sets his goals far above his abilities.

Theoretical psychology in its present state must try to develop a system of concepts which shows all the characteristics of a Gestalt, in which any part depends upon every other part. As we do not yet have the knowledge of facts which really suffices to determine this system of concepts and as, on the other hand, this knowledge of "facts" cannot be acquired without developing this system of concepts, there seems to be only one way open: to proceed slowly by tentative steps, to make decisions rather reluctantly, to keep in view always the whole field of psychology, and to stay in closest contact with the actual work of psychological research.